What reportedly happened: The flight instructor was conducting a biennial flight review with the commercial pilot. The CFI, who had logged 6,000 flight hours, held an ATP certificate, multi-engine, instrument, and seaplane ratings, as well as a CFI certificate for single and multiengine airplanes, and instrument airplanes. The pilot receiving instruction held a commercial pilot certificate and had an instrument rating. He had logged 1,175 hours, including 79 in make and model, three in the preceding 90 days,

A witness on the ground said the airplane flew overhead at an altitude of about 350 feet. The airplane rolled to the right and plunged into the ground nose first. A second witness, who was a first responder and was walking in close proximity to the accident site, reported hearing the ground impact behind him, but was unaware that it was an airplane that had crashed, as he did not hear any engine noise prior to the impact. The witness reported smelling fuel and observing a pool of fuel forming under the wings after reaching the wreckage. Another first responder reported that he smelled fuel as he approached the wreckage. GPS data revealed that the airplane had performed a four-turn spiral over the airport prior to the descent to ground impact.

Examination of the wreckage disclosed impact signatures and ground scars consistent with a stall/spin.

Probable cause: The pilot’s failure to maintain adequate airspeed while maneuvering, which resulted in an aerodynamic stall/spin.